Only vol. 2 has imprint date 1780.

Vol. 1 has 9 gatherings, signed OA-OI*8, and numbered CCXXV-CCCLXVIII, bound between p. 224 of part 1 (O8v) and p. 225 (half-title of part 2)

With half-titles, head- and tailpieces.

Vol. 1 first published 1778, under title: Lettres physiques et moreles sur les montagnes et sur l'histoire de la terre et de l'homme.

"Avertissement:" v. 1, p. [vii]-viii.

"Avis au lecteur," at end of v. 1, part 1, discours XIV: p. [CCCLXIII]-CCCLXVIII.

With dedication of 1st edition, dated 1er janvier 1778.

Copy 1 Vol. 1 Note: Vols. ii and iii have second half-title 'Lettres physiques et morales, sur les montagnes, etc.'; this was used as title for a volume published separately in 1778 but originally intended to be pt. i of this work.